1. Field of Invention
The present invention relates generally to a printer that prints on a recording medium such as paper, and relates more particularly to an inkjet printer in which the platen opposite the inkjet head has a suction mechanism for holding the recording paper, and relates further to a method of transporting the recording paper in this inkjet printer.
2. Description of Related Art
Printers that hold and print to recording paper that is wound in a roll (“roll paper” below) convey the recording paper pulled off the roll through a transportation path passed a printing position at the platen opposite the print head and a cutting position near the roll paper exit. In order to prepare for the next print job after cutting the printed paper at the cutting position by means of an automatic paper cutter, printers of this type according to the related art reverse the leading end of the paper after cutting off the printed portion from the cutting position toward the printing start position (the print head position) and then wait for the next print job with the paper set to the printing start position.
The end of the recording paper may also be curled. The end of recording paper that is wound into a roll in particular tends to curl, and such curling increases when relatively stiff paper is used. When the leading end of the roll paper is rewound to the printing start position, the leading end is left at the platen without being held by the paper feed rollers. Because the leading end of the paper is curled when thus left at the platen, the curled paper leads to paper jams or interference with the print head, and can thus cause printing problems. Japanese Unexamined Patent Appl. Pub. JP-A-2007-153602 therefore teaches an inkjet printer that has a suction mechanism for pulling the recording paper tight to the platen surface through holes disposed in the surface of the platen in order to hold the end of the paper pulled from the paper roll flat against the platen at the printing position.
The inkjet printer having a platen with a suction mechanism as taught in JP-A-2007-153602 prevents the recording paper from lifting off the platen by means of suction when in the standby mode with the leading end of the paper retracted to the printing start position. However, when this standby mode lasts long enough that the printer enters a power conservation mode or the printer power turns off, interruption of the power supply also causes the suction mechanism of the platen to stop operating. When this happens the paper is not held to the platen, allowing the leading end of the paper to curl and lift away from the platen surface. When the power conservation mode ends or the power turns on again to resume printing, the curled paper tends to interfere with the print head or paper feed rollers, resulting in a paper jam or possibly defective printing.